Have you by chance updated the firmware for your device? It sounds like you're having quite a few issues with it, so you may want to update the firmware and the drivers for your hardware to see if that helps.
If you're running Backup Exec 11d ver 7170, the latest driver pack can be found at http://support.veritas.com/docs/288038
If you're running build 6235, you may want to consider updating to the most recent build and then installing the most recent driver pack.
Regards,
Scott